The root element of all XSL-FO documents is fo:root . This element normally declares the fo prefix mapped to the http://www.w3.org/1999/XSL/Format namespace URI. As always, the prefix can change as long
as the URI stays the same. In this chapter, we assume that the prefix
fo has been associated with
http://www.w3.org/1999/XSL/Format.
Thus, a typical FO document looks like this:
<?xml version="1.0" encoding="UTF-8"?> <fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format"> <!-- Formatting object elements --> </fo:root>
Of course, normally this isn't written as directly as it is here. Instead, it's formed by an XSLT template like this one:
<xsl:template match="/">
<fo:root>
<xsl:apply-templates/>
</fo:root>
</xsl:template>The fo:root element must
contain two things: a fo:layout-master-set and one or more fo:page-sequence s. The fo:layout-master-set contains elements
describing the overall layout of the pages themselves; that is, how
large the pages are, whether they're in landscape or portrait mode,
how wide the margins are, and so forth. The fo:page-sequence contains the actual text
that will be placed on the pages, along with the instructions for
formatting that text as italic, 20 points high, justified, and so
forth. It has a master-reference
attribute identifying the particular page master that will be used to
layout this content. Adding these elements, a formatting objects
document looks like this:
<?xml version="1.0" encoding="UTF-8"?>
<fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">
<fo:layout-master-set>
<!-- page masters -->
</fo:layout-master-set>
<fo:page-sequence master-reference="first">
<!-- data to place on the page -->
</fo:page-sequence>
</fo:root>The formatting engine uses the layout master set to create a
page. Then it adds content to the page from the fo:page-sequence until the page is full.
Then it creates the next page in the sequence and places the next
batch of content on that page. This process continues until all the
content has been positioned.